Wong graph

In the mathematical field of graph theory, the Wong graph is a 5-regular undirected graph with 30 vertices and 75 edges. It is one of the four (5,5)-cage graphs, the others being the Foster cage, the Meringer graph, and the Robertson–Wegner graph.

Like the unrelated Harries–Wong graph, it is named after Pak-Ken Wong.

It has chromatic number 4, diameter 3, and is 5-vertex-connected.

The characteristic polynomial of the Wong graph is

${\displaystyle (x-5)(x+1)^{2}(x^{2}-5)^{3}(x-1)^{5}(x^{2}+x-5)^{8}.}$